Mike Johanns, the US agriculture secretary, likes to refer to his humble farm upbringing in the grain and livestock-rearing state of Iowa. He and his two brothers would often find themselves wielding pitchforks in the family's cowshed, "knee deep in you-know-what, pitching away".

While such homespun tales have helped him to connect with US farmers, they have done little to win grassroots farming support for the Bush administration's desire for a far-reaching overhaul of government support for agriculture.